SUPPLEMENT PROJECT SUMMARY Severe acute respiratory coronavirus 2 (SARS-CoV-2, also named as Coronavirus disease 2019 virus (COVID-19)) initially emerged in China in late 2019 and has rapidly spread to more than 70 countries in early March, 2020 with over 80,000 confirmed human cases world-wide. The World Health Organization has declared COVID-19 disease as a Public Health Emergency of International Concern. Neither effective vaccines nor treatments are available. A recent study of COVID-19 patients reported a close correlation of high levels of circulating inflammatory cytokines with the severity of illness in patients infected with the virus. This suggests the virus-induced cytokine storm may serve as a therapeutic target of COVID-19 diseases. Pellino-1 (Peli1), an ubiquitin ligase mediates inflammatory cytokine responses in multiple cell types, including lung epithelial cells and central nervous system resident cells. We have previously demonstrated that Peli1 induces microglia activation and promotes lethal encephalitis during West Nile virus infection. Peli1 also mediates inflammatory cytokine responses in bronchial epithelial cells and alveolar macrophages during influenza virus and rhinovirus infection. Neutralization of Peli1 attenuates virus-induced airway inflammation. The goal of the parent grant is to understand the role of Peli1 in mediating inflammatory cytokine responses in Zika virus - infected human neural stem cells and induction of congenital zika syndrome in animal models. In this supplement project, in collaboration with Dr. Vineet Menachery, an expert in coronavirus biology, we will investigate the role of Peli1 in COVID-19 disease. Specifically, we hypothesize that Peli1 mediates inflammatory cytokine responses in airway epithelial cells upon SARS-CoV-2 infection and blocking Peli1 signaling reduces airway inflammation and attenuates COVID-19 disease in mice. In Aim 1, we will determine the role of Peli1 following in vitro SARS- CoV-2 infection in human lung epithelial cells. In Aim 2, we will determine the therapeutic effects of Smaducin6 in animal models of SARS-CoV-2 infection. Initially, we will characterize SARS-CoV-2 infection in aged BALB/c mice. Subsequently, we will determine if treatment with Peli1 inhibitor attenuates COVID-19 disease in mice. Results from this study will provide important insights into CoVID-19 pathogenesis. In addition, identifying the mediators responsible for alterations in lung inflammation is key to prevention and treatment of CoVID-19 diseases.